1. Introduction
Buildings are inextricably linked to present human existence, as people live over 90% of their time indoors [
1,
2]. High-rise buildings, traditionally defined as structures with many floors that are greater in height than the neighbouring buildings, have evolved to be increasingly prominent in urban regions in emerging countries in the tropical region, like Sri Lanka in the past few decades [
3]. Rapid urbanisation, population increase, and economic growth have all led to the creation of high-rise buildings in key cities such as Colombo, Kandy, and Galle [
4]. Although these structures provide a variety of functions, including commercial, residential, and combined use, these slew of high-rise buildings have been added to the urban fabric with no regard for climate sensitivity or environmental implications [
3]. Therefore, the current situation is accelerating and generating more adverse circumstances for individuals along with the environment [
3]. Thus, climate change is capable of having a negative impact on the materials that compose the facades of buildings, causing degradation and damage [
5]. Moreover, these effects of climate change on facade building material degradation can result in occupational health and safety (OHS) issues for facade maintenance employees as exposure to defective or degraded facade materials can raise the likelihood of injuries and accidents throughout facade maintenance activities [
5]. As a result, facade maintenance employees must be aware of the possible risks resulting from climate change-induced degradation of facade materials and take appropriate safety measures throughout their daily operations.
Accordingly, the world is vulnerable to rapidly varying climate change that impacts humans and various industries [
6]. At present, sudden variations in general climatic conditions that are capable of causing catastrophic impacts at unexpected levels are experienced around the world [
7]. Thus, most people have seen climate as an unpredictable element that has the capability to bring both hazards and opportunities to mankind [
6]. Thus, the impacts of climate change can be identified at almost all levels; world, region, country, and municipal units that have specified the requirements for a multi-level set of actions [
8]. Accordingly, climate change can be described as the changes in the prolonged average natural weather conditions over the defined variation levels [
9]. Thus, inadvertent actions of human beings are the major cause of the occurrence of climate change [
6]. However, two major causes for climate change can be identified, namely, anthropogenic causes (deforestation, fossil fuel burning, variations in land usage, industrial activities, and forest degradation), and natural causes (variations in solar radiation and eruption of volcanoes) [
10]. Accordingly, the average global temperature has aroused since the middle of the 20th century as a result of the increase in the concentration of greenhouse gases (GHGs), namely, methane, carbon dioxide, and nitrous oxide since 1750 [
11]. Because the temperature at the surface of the Earth and troposphere is increased and also the stratosphere is decreased with the increase in the atmosphere’s GHG concentration like carbon dioxide [
12]. Furthermore, the precipitation, water cycle, and evaporation patterns of the Earth also accelerated at the same time [
12]. GHGs are emitted into the atmosphere through various human activities, namely, power generation, deforestation, land use practices, agricultural practices, forestry, construction, and other industry practices, burning of fossil fuels, and natural processes, namely, respiration, etc. [
13].
The contribution of Sri Lanka to the emission of GHGs is negligible as per the records of the Ministry of Forest and Environment [
14]. However, vulnerability to climate change is considerably higher in tropical countries, such as Sri Lanka, where numerous extreme weather conditions such as cyclones, droughts, floods and lightning have been experienced with an increasing frequency [
10]. Accordingly, consequences of climate change are experienced in all areas of Sri Lanka with resultant temperature variations being recorded generally in the lowlands in Sri Lanka resulting in temperature fluctuations concerning the rise of altitude [
10]. Thus, climate change is a complicated and multidimensional issue that has an effect on several facets the lifestyles, such as the built environment [
15]. Accordingly, building facades, that are subjected to a variety of environmental stresses as well as strains, are especially susceptible to the consequences of climate change [
15].
By blocking off undesirable exterior climate variables, the building envelope performs an important role in producing acceptable internal surroundings [
3]. Therefore, the overall performance of the building is considerably dependent on the facade components’ performance [
16]. Thus, special consideration should be given to facade maintenance also as the facade is an important element of a building that directly affects comfort, performance, and aesthetic appearance, and the facade’s overall performance is directly affected by the maintenance works which are performed for the facade [
17]. Moreover, facade materials might include stones, brick, glass, concrete, metallic material, and composite components, and the material selection is influenced by considerations such as endurance, appearance, energy conservation, and budget [
18]. Technological and material advancements have enabled new facade designs including double-skin facades, green facades, and smart facades, which include characteristics such as insulation, shading, and capture of energy [
19].
Temperature increases, extreme weather conditions including hurricanes, heavy precipitation, and continuous moisture exposure are all factors that may have an impact on the performance and longevity of facade materials, leading them to erode or degrade [
5]. Accordingly, the increasing degree of severity and frequency of catastrophic weather events is one of the most significant impacts that climate change has on facade building materials [
20]. Buildings are subjected to greater wind pressure, excessive moisture levels, and even more severe ultraviolet (UV) radiation as temperature increases and weather conditions become more erratic [
15]. These environmental pressures may lead to a variety of issues with building facades, including cracking, deformation, rusting, and deterioration [
20]. Moreover, climate change can have indirect impacts on building materials along with these direct effects, for example, rising sea levels, and varying patterns of precipitation can cause increased humidity and moisture destruction in buildings, especially those in coastal or low-lying territories [
20]. Accordingly, variations in air quality and levels of pollution, on the other hand, can hasten the degradation of building materials, especially those composed of highly permeable materials such as stone or brick [
20].
The limited research that has been conducted to study the effect of climate change on facade building materials used a variety of research methodologies to study the impacts of climate change on different kinds of facade building materials such as wood, masonry, and metallic materials, such as field investigations, laboratory tests, numerical models, and literature reviews. Despite the beneficial findings gained from existing research, various limits and flaws must be addressed. One disadvantage is the paucity of long-term field research that directly quantify the effects of climate change on facade materials over long periods. Most research relies on models or laboratory trials, which may not accurately represent the intricate relationships between climate change and facade material deterioration in real-world situations. There is also a lack of consistency in research methods and criteria for assessing the impact of climate change on facade materials. Different research may employ various methods for measuring, climate situations, and deterioration models, making it difficult to make comparisons and generalise findings across investigations. Furthermore, the vast majority of previous study has concentrated on particular kinds of facade materials or geographies, which may limit the findings’ applicability to other facade materials. Further study is also needed on the OHS implications on facade maintenance employees from impacts of climate change on facade materials depicting a considerable knowledge gap in this area. Considering the limitations that currently can be identified in existing research, there is an urgent need for further studies on the influence of climate change on facade building materials. Accordingly, the aim of this study is to identify the potential impacts of climate change on different facade building materials along with the OHS risks that can cause by these impacts on facade building materials. This study will help to directly quantify the effects of climate change on facade materials in real-world circumstances, utilizing established climatic scenarios. This could result in more precise and trustworthy information on the rates, mechanisms, and effects of climate change on various kinds of facade materials. Moreover, this study will help to make a significant contribution to knowledge regarding this significant research arena that should be given more attention by researchers in the present context and notify potential approaches for adapting facade materials to climate change challenges.
4. Results
4.1. Facade Building Materials and Maintenance
Thus, as per the responses of the experts, aluminium, block walls, and claddings made up of glass and aluminium, glass, precast concrete, steel, and timber are used in the facades of Sri Lankan buildings. According to the perceptions of the experts, various facade maintenance activities are performed in Sri Lanka, viz. cleaning of glasses, claddings, and precast facade finishing, changing facade’s colours, painting of the external walls, waterproofing of facades, removal, repairing or replacement of panel boards, silicon rectification, conducting periodic inspections, and removing salts, dust and other residuals.
Thus, the chemicals that are applied for the cleaning of glasses and claddings are varied from each other due to the inability to apply heavy chemicals on claddings as those claddings and their applied paints can be damaged from the application of heavy chemicals. Furthermore, the top sole of glasses can be damaged from the application of heavy chemicals on glasses. Therefore, more consideration should be provided in the selection of chemicals for the application on both glasses and claddings and light chemicals should be preferred. Moreover, if claddings have not been maintained for a considerable period, bringing those claddings to the previous state is considerably difficult and, in such situations, both cleaning and painting have to be performed to bring back the claddings near to the previous conditions. Therefore, regular maintenance activities should be performed for the claddings. Accordingly, as a summary, various maintenance activities based on the type of facade material can be stated in
Table 4 below.
4.2. Impacts of Climate Change on Facade Building Materials and Adaptation Measures
As a result, climate change has a considerable impact on the built environment, particularly the materials used in building facades. Extreme weather phenomena which include extreme heat waves, droughts, and high rainfall are growing increasingly frequent as the Earth’s climate continues to alter. These changes have the possibility of having an enormous effect on building facades and the materials often used to build them. Thus, extreme weather events, such as severe storms, floods, and heat waves, are putting pressure on building materials to endure changing climate conditions. Thus, as per the findings from the expert interviews, a considerable impact of climate change on the facade building materials can be identified.
Accordingly, concrete and brick expand and contract as temperatures rise causing structural failure and damage to the facade. Furthermore, extreme weather events, such as wind-blown particles or debris, can lead to structural harm to the facade. Rising moisture and humidity are other effects of climate change on facade building materials. As temperature increases, humidity levels rise, allowing mould and mildew to grow on the facade. Furthermore, changes in precipitation can cause water damage to the building’s facade, especially if the structure is not appropriately constructed to withstand runoff. The energy consumption of facades can also be affected by climate change. Buildings may need a greater amount of energy to cool as temperatures continue to rise, resulting in higher energy costs. Accordingly, as a summary, various climate change impacts on facade building materials can be presented in
Table 5.
Accordingly, water- or oil-based paints that are capable of withstanding different climatic variations, namely, higher moisture contents and temperature variations or self-cleaning paints with self-cleaning capability can be applied on facade panels. Furthermore, proper glass cleaning activities must be performed to remove fungi, dust, salts, and numerous other residuals on glasses which are created as a result of the deposition of raindrops on glasses, as such creations on glasses have an impact on the aesthetic appearance of the facades. Furthermore, the appropriate waterproof coating should be applied to avoid water infiltration into the interior of buildings through facades. To prevent timber, glass and aluminium facades from moisture absorption and solar heating, architects and developers can integrate climate-responsive elements such as overhangs and shading devices. In addition to the aforementioned operations, the removal, replacement, or repair of facade panel boards is conducted as needed. Penetration of water to the interior of the building from the facades is prevented with the aid of waterproofing applications.
Moreover, necessary attention should be paid to the delivery of appropriate maintenance activities for facade building materials to avoid the occurrence of these kinds of unexpected incidents. As such, based on the study findings an adaptation and mitigation strategy development workflow was developed, as shown in
Figure 3.
4.3. OHS Risks on Facade Maintenance Workers by Climate Change Impacts on Facade Building Materials and Adaptation Measures
The below spider diagram in
Figure 4 shows an excerpt from the full list of OHS risks for facade maintenance workers from climate change impacts on facade building materials that can be identified at the building-level operation of facade maintenance workers. Thus, a considerable number of OHS risks for facade maintenance employees are caused due to the climate change impacts on facade building materials with the scaffoldings, gondolas, ropes, and boom trucks access maintenance work, and if appropriate safety precautions are not adopted, it will be cause for the occurrence of injuries and even deaths of the employees and people on the ground level.
An excerpt of possible causes and impacts of identified OHS risks for facade maintenance workers that are caused by climate change impacts on facade building materials is shown in
Table 6.
Accordingly, during the current study, 75 adaptation measures were proposed to address the identified 15 significant occupational health and safety (OHS) risks exacerbated by climate change impacts on facade building materials. Furthermore,
Table 7 shows an excerpt from the full list of climate change adaptation measures that can be adopted at the building level for the safe operation of facade maintenance workers in safe and resilient buildings for the OHS risks caused by the climate change impacts on facade building materials.
Accordingly, employers and workers in the facade maintenance business must be aware of possible OHS concerns linked with the effects of climate change on facade construction materials and implement suitable mitigation measures. Various such adaptation measures, namely, fixing appropriate signage boards and tapes to avoid entering of people to the area of facade maintenance, provision of facilities for emergency communication, inspecting employee’s medical conditions, provision of life insurance for employees, and provision of adequate PPE, namely, safety boots, safety helmets, gloves, face shields, goggles, safety belts, and full-body harness are some of the climate change adaptation measures that are currently practised and can be added to the current list of such measures for the protection of the facade maintenance employees from OHS risks that are generated from the climate change impacts for the facade building materials.
Furthermore, adequate education and training should be provided for the facade maintenance employees on best practices on OHS and facade maintenance with the intention for the provision of safety at heights in the case of facade building materials. This may additionally involve the implementation of safety regulations, and the adaptation of workplace procedures to adapt to changing climate circumstances. Compliance with state OHS legislation and recommendations is critical to ensuring the safety and health of facade maintenance workers amid the effects of climate change. Therefore, the facade maintenance industry as well as the wider building industry can gain considerable advantages by adhering to these measures which will lead to the provision of maintenance activities effectively and efficiently without any hindrances, while safeguarding the safety of its employees.
5. Discussion
Accordingly, climate change is predicted to have worse consequences for the built environment, including building materials [
26]. Thus, changing climate trends are attributed to high humidity levels, temperature variations, and weather extremes such as floods and storms, all of which can impact the durability and life expectancy of facade building materials [
26]. Therefore, architects and designers must take into account the effects of climate change on facade materials when designing new buildings or retrofitting existing ones. Because choosing materials that are resistant to temperature variation, humidity, wind pressure, and UV radiation can facilitate that building persists structurally sound and visually appealing over time which in return will also help for the safe performance of facade maintenance activities by workers.
Furthermore, 34% of the defects of facades are due to design errors, 24% of the defects of facades are due to the unsuitability of facade materials, 19% of the defects of facades are due to construction errors, 16% of the defects of facades are due to the climate conditions, and 7% of the defects of facades are due to the maintenance malpractices [
76]. Accordingly, facades are subjected to various climate change impacts, namely, rainfall, UV rays emission, extremes of heat, etc. [
76]. As per the experts, climate change may also exacerbate existing building material issues, such as the expansion and contraction of materials due to temperature changes, which can lead to cracking and deformation.
Higher deterioration is one of the most considerable effects of climate change on facade building materials. However, it is essential to differentiate the climate change impacts from the ageing impacts of facade building materials. Because climate change effects and ageing effects on facade building materials represent two independent but connected issues. While the effects of climate change might hasten the process of ageing of facade building materials, these are not the same. The effects of climate change on facades are external variables which could contribute to facade building material ageing and worsen deterioration mechanisms [
77]. Thus, consequences of changing climatic conditions, which include higher temperatures, moisture, solar radiation, and adverse weather conditions, upon the durability and performance of facade construction materials are referred to as climate change impacts. The natural deterioration and degradation of materials with time owing to numerous causes such as being exposed to ambient elements, wear and strain, and chemical interactions are referred to as the ageing of facade construction materials. Climate change effects are external variables that might hasten the deterioration of facade materials, whereas ageing is a natural process which happens with time irrespective of changes in the climate. Regardless of the absence of severe climate change, facade materials can age; however, climate change can amplify the impacts of ageing and contribute to faster material deterioration.
One of the most significant impacts of climate change on facade building materials is the increasing temperature fluctuations [
78]. Severe heating and cooling conditions can affect materials to expand and contract resulting in cracking, and warping, as well as other types of damage and prolonged exposure to high temperatures can induce materials to deteriorate and diminish, minimizing their life expectancy [
78]. This is especially critical for organic materials such as timber as well as plastics, which are more especially vulnerable to thermal decomposition. Materials of high thermal properties, such as metals, on the other hand, can be affected by temperature changes. For example, metals can discover high-temperature fatigue, which can lead to corrosion and other types of damage [
79]. This will also cause the occurrence of various unexpected OHS risks for facade maintenance workers leading them to injuries and even deaths.
Climate change is also causing changes in precipitation patterns, which can lead to increased moisture and humidity levels [
80]. Moreover, high rates of humidity could indeed affect facade building materials to decompose, corrosion, and discolouration, resulting in structural destruction and health consequences [
80]. According to the experts, facade building materials, namely, brick, concrete, and masonry are highly susceptible to water penetration, which can occur cracking, erosion, discolouration, structural damage, and decay over time. Moreover, some timber and metals may be susceptible to corrosion in various climatic conditions.
Extreme weather events, such as hurricanes and storms, can generate high wind loads on building facades [
81]. Accordingly, it can cause facade materials to deteriorate, especially those not designed to withstand high wind loads [
81]. For example, lightweight materials, such as metal cladding and glass, are highly susceptible to wind loads and may require additional support to prevent damage. Furthermore, changes in wind patterns occurring by climate change can cause problems with wind-driven rain and humidity penetration, exacerbating humidity problems. As climate change affects the amount of UV radiation that materials are exposed to, UV radiation can cause fading and discolouration of materials, especially those that are not capable of withstanding prolonged exposure to sunlight. This is especially important for facade materials such as plastics, paints, and coatings [
82]. Thus, these impacts are capable of posing significant hazards to facade maintenance employees including physical harm, health concerns from exposure to hazardous substances or contaminated water, along with other hazards linked with poor weather events.
Therefore, building landlords and maintenance experts are launching innovative strategies for facade maintenance which incorporate the unique difficulties caused by climate change in order to address these challenges [
83]. Thus, various strategies can be used to mitigate or minimise the climate change impacts on facade building materials. These could involve the implementation of more durable materials, upgraded weatherisation and insulation methods, as well as the creation of sophisticated coatings and other safety precautions to minimise the effects of humidity, UV radiation, as well as other environmental exposures [
83]. The use of materials that are more tolerant of humidity and temperature fluctuations, such as composite materials or highly specialised coatings, is one approach [
26]. Another method is to design buildings with improved ventilation and insulation systems in order to minimise the effects of moisture and temperature variations on building materials [
84]. This encompasses the utilisation of low-embodied carbon materials such as timber, bamboo, and recyclables [
84]. Thus, the use of such materials can assist in lowering not only the impact of climate change on the built environment but also carbon emissions. In addition, the experts stated that ongoing maintenance activities can help to prevent climate change issues and made sure that buildings work more efficiently and effectively and safely for occupants. Furthermore, as a response to climate change, utilizing sustainable building materials is becoming increasingly important.
As per the National Institute for Occupational Safety and Health (NIOSH), the risks to facade maintenance employees include falls from great heights, exposure to hazardous substances, and electric shocks [
85]. Moreover, the destruction of facades caused by climate change can aggravate these dangers [
85]. In addition, the frequent occurrence of hurricanes and windstorms, for example, could indeed affect facades to also be loose or damaged, raising the likelihood of falls for workers who work at heights [
85]. Furthermore, intense temperatures and torrential rain can deteriorate or degrade substances such as concrete and masonry, raising the probability of destruction or falling debris while increasing the OHS risk of facade maintenance workers [
85]. Accordingly, as per the experts, a considerable number of risks are generated for the facade maintenance workers due to the climate change impacts on facade building materials. These OHS risks are capable of causing injuries and even deaths for the facade maintenance workers, building occupants as well the surrounding people and property.
In summary, the climate change impact on facade building materials is an important consideration for the built environment. Accordingly, in the face of changing climate patterns, it is essential to take into account the durability and sustainability of building materials. It is effective in reducing the impact of climate change on facade building materials by using materials that are resilient to humidity and temperature variances, improving building ventilation and insulation systems, and implementing sustainable building practices. Thus, appropriate risk management approaches can assist in minimizing threats from climate change impacts on facade building materials while guaranteeing worker safety. This could include performing regular risk assessments, incorporating rigid safety precautions for continuing to work with hazardous materials, and providing workers with continuous education, assistance, and training.
6. Conclusions
This study has investigated the effects of climate change on facade building materials, as well as the accompanying OHS issues for workers in facade maintenance. Climate change, alongside its altered climate trends such as rising temperature and sustained UV radiation exposure and advancing severity of extreme weather conditions including storms, heatwaves, as well as heavy rainfall, has the capability of impairing the durability, functionality, and maintenance and causing physical damage including fractures, erosion, and dislocation of facade building materials such as paint, coatings, sealants, as well as adhesives, potentially increasing the risks for employees who perform facade maintenance activities. In addition, variations in precipitation patterns and increasing levels of humidity can cause moisture-related difficulties including mould growth and decay, which can endanger workers’ health and compromise the integrity of facade materials.
Climate change has a significant impact on facade building materials, and architects and designers must consider these impacts when selecting materials for new buildings or retrofitting existing ones. Building-level transformation controls that can be executed to make buildings safer and more resilient should be given special consideration. In establishing such adaptation strategies, the case of facade maintenance was chosen because of the noteworthy impacts faced by facade building materials as facade maintenance work has grown increasingly challenging because of the establishment of advanced facades using advanced technologies, and as climate change has been identified as one of the significant contributors to the facade building materials. Because, according to predictions, the world is facing unexpected risks from climatic changes at an ever-increasing rate. As a result, appropriate practice is required. As a facade is a crucial building element that significantly influences building performance, choosing appropriate adaptation to climate change measures will be beneficial in order to optimally perform facade maintenance tasks without any hindrances. Furthermore, these measures will pave the way for facade maintenance employees to be protected from unanticipated accidents and other difficulties caused by climate change. As a result, the findings of this study will provide immensely valuable aspects for the advancement of the FM sector. There is a growing body of research on this topic, and further studies are needed to understand the long-term impacts of climate change on building materials. Therefore, while the current study is from Sri Lanka, the findings can help to develop climate change adaptation measures in FM industries in other tropical countries.